Bag for bulk material

ABSTRACT

A bag ( 1 ) for bulk material, in particular animal feed and/or foodstuffs, with a flexible bag wall ( 2 ) and a re-closable removal opening for removing the bulk material from the bag ( 1 ), wherein the removal opening is designed as a flap ( 3 ). The flap can be folded together about a fold axis ( 8 ) and can have a valve ( 12 ).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No. PCT/AT2008/000275, filed Aug. 6, 2008, which claims the benefit of Austrian Patent Application No. A1256/2007, filed Aug. 10, 2007, both of which are incorporated herein by reference as if fully set forth.

BACKGROUND

The present invention relates to a bag for bulk material, in particular, animal feed and/or foodstuffs, with flexible bag walls and a reclosable removal opening for removing the bulk material from the bag. In addition, the invention relates to a flap that is suitable as a reclosable removal opening for a container for bulk material.

In the case of the state of the art, it is known to purchase bulk material sealed in a bag, such as, e.g., dog or cat food or other foodstuffs for people or animals. These bags have flexible bag walls. The contents are usually provided for successive consumption over a long period of time. In order to be able to reclose the bag after removing a portion of the bulk material, that is, e.g., after removing a portion of animal feed, in the state of the art, reclosable removal openings are known in the form of slide-fastener-like zippers usually made from plastic.

Previously common reclosable removal openings are difficult to handle, especially when the bag has already been partially emptied, and also often hinder the refilling of the bag.

SUMMARY

The objective of a first aspect of the invention is therefore to disclose a reclosable removal opening for bags according to this class, wherein this opening avoids the disadvantages noted above for the state of the art.

According to a first aspect of the invention, this is achieved in that the removal opening is constructed as a flap.

The flap has the advantage that it can be reclosed in a simple way also in a partially emptied state of the bag or it is automatically reclosed in the case of an appropriate biasing tension. The flap is here understood as, in particular, at least two components that are connected in an articulated way to each other and that can pivot or unfold relative to each other, wherein, in a first position, one component at least partially closes an opening in the other component and, in the other position, at least partially opens this opening. The bulk material that can be stored in bags according to the invention can have a varying consistency. Here, the material can involve, e.g., granular material whose grain size can be very different. This usually lies in the sub-millimeter, millimeter, or centimeter range. However, it is also conceivable to use bags according to the invention for liquids, emulsions, or the like as bulk material. The invention is in no way limited to bulk material such as animal feed and/or foodstuffs, it could also involve, e.g., laundry detergent powder, dishwasher detergent powder, or liquid laundry or dishwasher detergents and the like, to name only a few examples.

The removal opening according to the invention is primarily provided for discharging bag contents. For a corresponding size of the removal opening, however, it could also be provided that one could reach into the bag interior, in order to remove the bulk material from the bag. The bag is usually completely closed by sealing or bonding after being filled with the bulk material. After this sealing process, to open the bag, there is only the flap. In particular, in the case of animal feed and/or foodstuffs, after its production and after filling and sealing of the bag, the flap is initially completely closed at first, so that no gas exchange can take place through the flap, so that, in the sealed bag state after the filling process, the bulk material is stored gas-tight in this bag. Now it could be necessary according to the type of the bulk material to let air into the bag or out of the bag while the bulk material is stored in the closed bag, that is, before the first opening of the flap.

To allow this, an independent aspect of the invention provides that, in the case of a flap suitable as a reclosable removal opening for a container for bulk material, a valve is provided in the flap, advantageously in the flap door or in a flap frame, wherein this valve allows gas throughput in one direction, advantageously into the container, and blocks gas throughput in the opposite direction.

Such a flap could be used both for bags with flexible bag walls and also for containers with essentially rigid walls, such as, e.g., cardboard boxes or other cartons. The use of bags has the advantage that these could be folded together into a relatively small overall volume already in a partially emptied state. For containers with rigid walls, such as cardboard boxes or cartons, this is not possible. However, it is often provided to fold these containers together after complete emptying, in order to keep their waste volume as small as possible when they are disposed.

In this context, the objective of disclosing a flap is presented that likewise can be folded together as small as possible both for bags with flexible bag walls and also for other containers with essentially rigid walls.

This is achieved according to another independent aspect of the invention in that, in the case of flaps that are suitable as a reclosable removal opening for such containers, it is provided that the flap has a flap frame and a flap door that is attached to this frame and that can pivot relative to the flap frame about an imaginary flap axis, wherein the flap frame and/or the flap door can be folded about at least one folding axis, advantageously in a closed position of the flap door. Thus it is provided that, on one hand, the flap door can pivot relative to the flap frame for removing the bulk material, in order to be able to open and close the container. On the other hand, however, the flap frame and/or the flap door can be folded about at least one folding axis, above all in the closed position of the flap door, in order to be able to fold the flap as a whole as small as possible.

The one or more folding axes of the flap can also lie basically parallel to or directly on the flap axis. Preferably, however, it is provided that the folding axis is arranged in the closed position of the flap door at an angle that is different from 0° and 180°, advantageously orthogonal to the flap axis. In the case of bags that have folds running advantageously in their longitudinal direction, it is favorable to arrange the flap in the region of the fold. Here it is especially preferred when the folding axes of the flap and the fold of the bag lie one on top of the other. This has the effect that the flap is automatically folded in the closed position of the flap door by the fold in the bag and the flap door is therefore held closed.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional details and features are shown with reference to the following figure descriptions. Shown here are:

FIGS. 1 to 3 are different views of a bag equipped according to the invention before being filled and the subsequent sealing of the bag, and

FIGS. 4 to 7 are different views and positions of a flap according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a bag 1 according to the invention before this is filled with the bulk material and is sealed or closed in some other way in the area between its upper edge 15 and the flap 3. FIG. 1 here shows a view into the interior of the bag of the flap 3 arranged in the region of the longitudinal fold 4. This flap has a flap frame 5 and a flap door 7 attached to this flap frame 5 so it can pivot. The pivoting attachment of the flap door on the flap frame is here constructed by means of a film hinge 9. However, other hinge-like connections between the flap door 7 and flap frame 5 could also be provided. In any case, it is favorably provided that the flap 3 is produced in one piece. For example, in the case of the flap 3 it could involve an injection-molded part made from plastic. Suitable plastics for the production of the flap 3 are, e.g., polyethylene or polypropylene. In this embodiment, the flap 3 or the flap frame 5 is welded from the inside onto the bag wall 2. Instead of the welding, bonding or also different types of connections could also be provided. The flap 3, however, does not absolutely have to be constructed as a standalone component. It is also possible to construct the flap 3 in one piece with the bag walls 2. The completion from initially two separate components, however, has the advantage that stiffer material could be used for the flap 3 than for the bag walls 2, so that the flap 3 is overall more dimensionally stable, which is favorable both for the discharge or removal of the bulk material and also for the reclosing.

For the bag walls 2, different composite or mono materials known in the state of the art could be used. In particular, for the animal feed and foodstuffs industry, composite materials with a carrier film made from polyester or polyamide and a barrier coating made from, e.g., metal, have proven effective. This, however, is in no way to be viewed as limiting. Other plastics, papers, paperboards, metals, or the like could also be used individually or in composite as the bag walls 2, to name only a few examples.

As is to be seen particularly well in FIG. 1, the bag walls 2 have folds 4. In order to be able to fold the bag 1 as small as possible in the partially or completely emptied state, it is preferably provided that the flap 3 which can be folded about the folding axis 8 is arranged on the bag walls 2 so that the folding axis 8 of the flap 3 essentially coincides with the fold 4 of the bag. Here it is to be seen that the fold 4 always has the tendency toward folding together, by means of which, for a closed flap door 7, the flap 3 is also automatically folded. Through this automatic folding, the flap door 7 is also folded together, by means of which it is automatically held in the closed position shown in FIG. 1. Another advantage of the illustrated arrangement of the flap 3 on the bag walls 2 is that the flap 3 does not interfere with the refilling of the bag.

FIG. 2 shows a view from outside onto the bag walls 2 before the bag 1 is filled. This is also the state before the first opening of the flap 3—as far as the area of the flap 3 is concerned. In this embodiment, the flap 3 is hidden behind a region of the bag walls 2 surrounded by the perforations 14. For the first-time opening of the flap, the bag walls 2 are initially ripped open in the region of the perforations 14, by means of which the flap 3 becomes visible and able to be gripped from the outside and can be opened.

FIG. 3 shows the bag 1 in the completely empty and folded-together state in which the flap 3 is also folded about its folding axis 8, so that, as a whole, the smallest possible volume is produced for the bag 1.

FIGS. 4 to 7 show the flap 3 in the state detached from the bag 2. As already explained, this embodiment of the flap 3 has a flap frame 5, as well as a flap door 7 attached to this frame by means of the film hinge 9 so that it can pivot. The flap door 7 can be folded or can pivot about the flap axis 6 specified by the film hinge 9. For activation, the grip region 11 is formed on the flap door 7 so that it can be gripped from the outside also in the closed position of the flap door 7 and simplifies the opening and closing of the flap door. FIG. 4 shows the flap 3 in the opened position of the flap door 7 in which the bulk material can be removed from the bag or poured out from it. For reclosing—to the closed position shown in FIG. 6—a peripheral flexible lip 10 is provided on the edge of the flap door 7 facing the flap frame 5 in the closed position. This engages behind the flap frame 5 in the closed position of the flap door 7, so that the flap door 7 is again held in the frame 5. Before the first opening of the flap door 7, the sealing lip 10 could be connected integrally with the flap frame 5, so that it rips open in the case of the first activation of the flap door 7 and is then used as a holding device for holding the flap door 7 in the closed position for the reclosing process.

Shown only with dashed lines are optional side walls 13 that are preferably made, if they are provided, from a flexible material. Through these side walls 13, a funnel-like opening could be created in the flap 3 together with the flap door 7, wherein this opening simplifies the targeted pouring of the bulk material in a specified direction. These side walls 13, however, do not necessarily have to be provided.

FIG. 5 shows a view from the inside, that is, from the bag interior of the flap 3 with an opened flap door 7. FIG. 6 shows—as already mentioned—the closed position. Here, it is particular easy to see that the imaginary folding axis 8 could be constructed in the form of a material reduction in the flap frame 5 and in the flap door 7. This embodiment thus involves a type of film hinge.

Both the flap axis 6 and also the folding axis 8 do not absolutely have to be constructed as exact axes in the mathematical sense. In reality they could definitely involve bendable, spatially extended regions, as is the case, for example, for film hinges. Instead of the illustrated film-hinge-like constructions, however, it is naturally also possible to provide other hinges that can pivot about exact axes. Independent of the embodiment, it is preferable, in any case, that the folding axis 8 and the flap axis 6 are designed for multiple cycles of folding and unfolding together, without resulting in material fatigue. Preferably, the flap 3 should also be able to be folded and unfolded together about the folding axis 8 at least 100 times, without resulting in breakage or material fatigue. The same naturally also applies for the film hinge 9 that allows folding about the flap axis 6.

As shown in FIG. 6, the flap axis 6 and the folding axis 8 are arranged orthogonal to each other in the embodiment illustrated here. This does not have to be the case, because any other angle is also conceivable.

FIG. 7 shows the state of the flap 3 folded together about the folding axis 8.

In order to allow a desired filling and release of air into and out of the bag interior after the filling and sealing of the bag 1 and before the opening of the otherwise advantageously gas-tight flap 3, according to one special aspect of the invention, a valve 12 is provided. This is arranged in the flap door 7 in the illustrated embodiment. However, it could also be provided just as easily in the flap frame 5 or in the region of the reduced walls of the folding axis 8 or the film hinge 9. In the shown embodiment, the valve 12 is constructed as a slot. This could be lasered, e.g., into the material of the flap 3. The slot or the valve 12 is constructed so that the gas throughput is allowed in one direction, that is, e.g., into the container or the bag 1, while the gas throughput is blocked in the opposite direction. In the case of strongly outgassing bag contents, it could also be provided that gas could be discharged from the bag interior through the valve 12 but cannot enter into the bag. Preferably it is provided that the valve opens only in the case of a differential pressure of at least 30 to 60 millibar between the bag interior space and the bag exterior space and is otherwise closed. In addition to the slot-like construction of the valve 12 shown here, however, all other valve types known in the state of the art and suitable for this application could naturally also be used in the flap 3.

The invention has been explained in the figure description with reference to a flap 3 constructed especially for bags 1 with flexible bag walls 2. As mentioned above, however, the illustrated flap 3 could also be used according to preferred aspects of the invention in combination with containers with essentially rigid walls.

LEGEND FOR THE REFERENCE SYMBOLS

-   -   1 Bag     -   2 Bag wall     -   3 Flap     -   4 Fold     -   5 Flap frame     -   6 Flap axis     -   7 Flap door     -   8 Folding axis     -   9 Film hinge     -   10 Flexible lip     -   11 Grip region     -   12 Valve     -   13 Side wall     -   14 Perforation     -   15 Upper edge 

1. Bag for bulk material, comprising a flexible bag wall and a reclosable removal opening for removing bulk material from the bag, and the removal opening is constructed as a flap, wherein the flap has a flap frame and a flap door that is attached to the frame and that can pivot about a flap axis relative to the flap frame, wherein at least one of the flap frame or the flap door can be folded together about at least one folding axis, wherein the bag has a fold and the flap is arranged in a region of the fold, and wherein the flap is an injection-molded part made from plastic.
 2. Bag according to claim 1, wherein the bag is completely closed, apart from the flap.
 3. Bag according to claim 1, wherein the fold runs in a longitudinal direction of the bag.
 4. Bag according to claim 1, wherein the flap frame of the flap is welded into the bag.
 5. Bag according to claim 1, wherein the flap frame of the flap is glued onto the bag.
 6. Bag according to claim 1, wherein the flap is welded onto the bag wall from inside in an interior of the bag or is connected to the bag wall from the inside by another connection.
 7. Bag according to claim 6, wherein the flap is hidden behind a region of the bag wall encompassed by perforations.
 8. Bag according to claim 1, wherein the flap frame is located around the flap door.
 9. Bag according to claim 1, wherein at least one of the flap frame or the flap door can be folded together about at least one folding axis in a closed position of the flap door.
 10. Bag according to claim 1, wherein, in a closed position of the flap door, the folding axis is arranged at an angle that is different from 0° and 180° relative to the flap axis.
 11. Bag according to claim 1, wherein, in a closed position of the flap door, the folding axis is arranged orthogonal to the flap axis.
 12. Bag according to claim 1, wherein a wall thickness of at least one of the flap frame or the flap door in a region of the folding axis is less than in a region of at least one of the flap frame or the flap door surrounding the folding axis.
 13. Bag according to claim 1, wherein the flap door is attached in a region of the flap axis by a hinge.
 14. Bag according to claim 1, wherein the flap door is attached in a region of the flap axis by a hinge film.
 15. Bag according to claim 1, wherein at least one of the flap frame or the flap door comprises polyethylene or polypropylene or consist thereof.
 16. Bag according to claim 1, wherein, for reclosing the flap, the flap door has a flexible lip on an edge thereof facing toward the flap frame in a closed position, and the lip keeps the flap door in the closed position in the flap frame.
 17. Bag according to claim 16, wherein the lip is connected in one piece to the flap frame before a first opening of the flap door.
 18. Bag according to claim 1, wherein a grip region is provided on the flap door, and the grip region can be gripped from outside, also in the closed position of the flap door and simplifies at least one of opening or closing of the flap door.
 19. Flap for constructing a reclosable removal opening for a container for bulk material, wherein a valve is provided in the flap, and the valve allows gas throughput in one direction and blocks gas throughput in an opposite direction.
 20. Flap according to claim 19, wherein the valve is constructed as a slot in the flap door or the flap frame.
 21. Flap according to claim 19, wherein the valve is constructed as a slot in the flap. 